


Simon’s Secret

by BloodWhitePanther



Category: Shadowhunters (TV), The Shadowhunter Chronicles - All Media Types
Genre: Accidental Voyeurism, Alley Sex, Angst and Fluff and Smut, Angst with a Happy Ending, Bars and Pubs, Being Walked In On, Best Friends, Blow Jobs in a Car, Brother/Sister Incest, Canon Het Relationship, Car Sex, Childhood Friends, Clary Fray & Isabelle Lightwood Friendship, Clary Wears Isabelle's Clothes, Clubbing, Coitus Interruptus, Confessions, Exhibitionism, Explicit Language, Explicit Sexual Content, F/M, Female Friendship, Friends to Lovers, Friendship/Love, Implied/Referenced Incest, Incest, Incest Kink, Isabelle Dresses Clary, Isabelle Lightwood Gives Good Advice, Jace Keeps Walking in on Them, Jace Wayland Feels, Jace Wayland Needs A Hug, Kink Negotiation, Light Angst, M/M, Male-Female Friendship, Mildly Dubious Consent, Minor Leia Organa/Luke Skywalker, Non-Explicit Sex, Possibly Pre-Slash, Pre-OT3, Pre-Poly, Pre-Threesome, Pseudo-Incest, Public Blow Jobs, Public Hand Jobs, Public Sex, Secrets, Semi-Public Sex, Sex God Simon Lewis, Sex in a Car, Sibling Incest, Slight Meta, Supportive Isabelle Lightwood, Under-negotiated Kink, Unresolved Sexual Tension, Vampire Simon Lewis, Voyeurism, What Would Jace Do, presumed incest
Language: English
Status: Completed
Published: 2019-05-09
Updated: 2019-05-09
Packaged: 2020-02-28 22:17:31
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,211
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18765370
Author URL: https://archiveofourown.org/users/BloodWhitePanther/pseuds/BloodWhitePanther
Summary: Simon is happy because Jace is Clary’s brother. He’s horny because he gets to kiss Clary. He’s definitely not horny because the last person his girlfriend kissed turned out to be her brother. Nope, no way, because that would be totally weird, right? And even if Simon were actually into that — if he had some kind of secret incest kink — he’d know about it, wouldn’t he? Apparently not. Apparently, he has kind of thing for it. A secret thing. A really kinky secret thing that’s totally not a big deal, okay?





	Simon’s Secret

**Author's Note:**

> Disclaimer: All recognizable characters, settings and concepts belong to the legal copyright holders. This is a fanwork, and I have not profited financially from its creation or distribution.

So apparently, Simon has kind of thing. A secret thing. A secret thing that’s totally not a big deal, okay? It’s just an embarrassing thing that he apparently has that he’d rather not admit to his amazing new girlfriend because it would, in all likelihood, really freak Clary out. Simon figures it would freak her out because it’s kind of a kinky thing. Okay, it’s actually a bit more than kind of kinky. It’s a really kinky secret thing that Simon wasn’t expecting to like.

He doesn’t have a lot of romantic experience — Maureen, Maia, Clary, a couple of kissing games in middle school and that’s really it — but in his limited experience, he’s never really had a thing for kink. In fact, Simon’s tastes before this have always been pretty vanilla. So he wasn’t expecting to like this thing as much as he does.

No, he definitely wasn’t expecting to like the fact that Clary and Jace are apparently brother and sister. I mean, of course, he should like it a little bit — to the extent that it means they had to break up — because there’s nothing wrong with being happy with the fact that Clary is free to date Simon now. At first, he hopes that’s all it is. He’s happy because Jace is Clary’s brother. He’s horny because he gets to kiss Clary. He’s definitely not horny because the last person his girlfriend kissed turned out to be her brother.

Nope, no way, because that would be totally weird, right? And even if Simon were actually into that — if he had some kind of secret incest kink — he’d know about it, wouldn’t he?

I mean, there was kind of a similar situation with Luke and Leia in _Star Wars_. But Simon didn’t know they were supposed to be brother and sister when they kissed in the movie. So what if he sometimes thought about that kiss after he knew they were related? They were just actors — actors playing fictional characters. It wasn’t real, so it wasn’t a thing that Simon had to worry about.

Until now, that is.

Because this is real, and Simon can’t stop thinking about it, and it’s beginning to freak him out. He’s like 75% positive that he shouldn’t be thinking about his girlfriend with another guy when he’s kissing her. And if he happens to think about his girlfriend with another guy — because let’s be real, that’s maybe kind of hot — he’s 99% positive the guy shouldn’t be her brother.

He tries to focus on something else — how much he loves Clary, how happy he is to finally be with her, how good it feels to kiss her anytime he wants. It works for a while because kissing Clary is undoubtedly amazing. But whenever things get too heated, his brain just tends to go there without his permission.

When Simon puts his tongue in Clary’s mouth, he can’t help but think _Jace was here first_. When Clary reciprocates, chasing Simon’s tongue back into his mouth, he wonders, _did she kiss Jace this passionately?_ When they progress to making out, to feeling each other up, to dry humping, he pictures Clary doing all those things with Jace. More than anything, he wants to know if they did, what they did — exactly what they did — but it’s definitely not okay to ask your girlfriend how far she got with her brother, so he keeps quiet and tries to deny it.

Denial doesn’t get you very far when the thing you don’t want to believe just keeps happening though, so eventually, Simon has to admit to himself that he maybe kind of has a thing for sibling incest. That doesn’t mean he has to admit it to anyone else. Things are really good with Clary, and he’d rather not rock the boat. Unless, you know, it’s the canoe in the boathouse and he and Clary are rocking it together. And the secret kinky thing that Simon has just really isn’t that important in the grand scheme of things.

Except, apparently, that thing is kind of important to Simon because he can’t stop thinking about it. Let’s be honest, every time he kisses Clary, at least half his brain power dedicates itself to the idea. And as if that isn’t enough, Jace keeps walking in on Simon and Clary when they’re alone together interrupting them before, during and after sexy times. To make matters unbearably worse, Jace seems even more upset about it than Simon is. It’s almost like he can’t stand to watch his sister kiss another guy, which kind of fries Simon’s brain a little.

After he comes to that conclusion, Simon spends the next week or so watching Jace really closely until he’s 95% positive that the dude is still pining for Clary — which would mean, if true, that he wants to fuck his own sister. Simon should not be okay with that. He should not do anything to encourage it. And most of all, he should not want to watch.

The only saving grace Simon has left is that Clary doesn’t seem to feel the same way. She honestly seems to see Jace like a brother more than an ex. Then again, Simon has never been able to read people as well as Clary can.

 

***

 

When Simon and Clary have sex for the first time, he actually forgets all about Jace for a solid day, maybe two. Making love to her is earthshakingly good. He’s imagined being inside Clary pretty much since the moment he learned what sex is, and the reality blows all his fantasies out of the water. It wipes his mind clean, filling his head and his heart with nothing but his love for her.

Sadly for Simon, once they’re sleeping together, Clary wants to talk about what Simon likes in bed, which leads rather rapidly to sharing sexual fantasies with each other. Logically and semantically speaking, it’s a very short path from sharing sexual fantasies to full-on kink disclosure, and Simon is beginning to worry. If you combine his limited romantic experience with the brevity of his past relationships, it doesn’t add up to kink disclosure, kink negotiation, or god forbid, kink exploration.

Simon doesn’t have any experience disclosing kinks to his girlfriend. He doesn’t know how to do that. In the case of this particular kink and this particular girlfriend, he doesn’t want to do that. Telling Clary, the girl who just fell out of love with someone because he turned out to be her older brother, that he kind of has a thing for sibling incest is definitely not a good idea. But he also doesn’t want to outright lie to Clary, and the way things are going, it’s getting harder to hide his dirty little secret.

It doesn’t help that Clary is unusually observant. Visual artists learn to notice the details. Shadowhunters play detective on a nightly basis. Best friends know how to read each other. These three things add up to someone who can read Simon as easily as a children’s book, and it won’t be long until she starts asking the right questions.

Admittedly, the conversation starts off okay. Clary tells Simon about some of her fantasies — positions she wants to try, a couple of sexy dreams she’d like to reenact, a fondness for wearing black lingerie. Simon is down with all that. Especially the lingerie, because with the way Clary lets Izzy dress her up in tight corsets and black leather, it’s not like he hasn’t imagined it before. And it isn’t like there’s a shortage of sexy things he’d like to do with her. He’s had years to dream up ideas, after all, and she seems to love hearing about them.

But Clary being Clary, she doesn’t stop there. She can tell Simon’s holding something back, so she asks him if he has any secret turn-ons, offering to try something kinky if he has anything specific in mind. He says something vague and stupid about not having a lot of experience with kink, but that just makes Clary more brazen. She gets specific on him — voyeurism, exhibitionism and public sex are some of the first things she asks about. Apparently, she’s noticed the way Simon gets extra turned on when they get interrupted.

And oh joy, apparently a well-fed vampire can blush just as well as a mundane because Simon feels his face heat up when she tells him she’s noticed that. He doesn’t want to lie to Clary — he really doesn’t — but what exactly is he supposed to say? Yeah, especially when it’s your big brother who catches us. Simon _cannot_ say that. So he does the honorable thing and pretends to have a kink for semi-public sex.

Simon doubts he’s much of an exhibitionist. He’s cool with a certain amount of PDA, but to be perfectly honest, when it comes to sex, he likes the comforts of home. But it’s not like it’s a complete hardship to get off with Clary wherever and whenever she wants.

First, they fuck in back of Simon’s van. It’s not exactly his cup of tea, but sex with Clary is still sex with Clary even if the back of the van is kind of dark and hard and full of mic stands, extension cords and amps. Then, she wants to try sucking him off in the front seat. Clary’s mouth is fantastic, she’s getting really good at blowjobs, and the windows are higher than Simon’s waist, so why not? It’s good but it’s also awkward and cramped, and Simon can’t really relax, and Clary can tell it isn’t really doing anything extra for him. He kind of hopes she’ll give up and take him back to her room at the Institute or the boathouse at the Jade Wolf.

He should really know by now that Clary isn’t one to give up easily. His girlfriend is smart and sexy and maybe some kind of nympho, what with the way she’s so determined to push Simon’s buttons. So she tells him she thinks she’s figured it out. Semi-public sex isn’t enough on it’s own — they need to do things in front of other people.

Simon sputters for a moment and then reminds Clary that they don’t want to get themselves arrested for public indecency. He has no desire for a criminal record, and perhaps even more importantly, under no circumstances does he want to discuss his kinky sex life with Luke. Clary laughs and says it won’t come to that. Apparently, she asked Isabelle for some tips, who told her that Pandemonium is a great place for public sex.

Simon wants to be mad about it, but honestly, the idea of Izzy telling Clary all about that time she got fingered on the dance floor or that time she fucked a guy in a bathroom stall is astonishingly hot. Hot chicks talking about their kinky sex lives with each other — specifically Clary talking to Izzy so she can better pleasure Simon in the future — is just objectively arousing. He kind of wants to ask if she’s ever gone to Izzy for kissing practice and blowjob tips, but it seems in poor taste. For the purpose of his bedtime fantasies, he’s just going to assume that she has.

As it turns out, Clary and Izzy may be on to something after all and Simon may be kinkier than he thinks. Fingering Clary in the shadows of the club is way hotter than having awkward sex in his van. Maybe, it’s because they’re surrounded by unsuspecting strangers. Maybe, it’s because he knows that Clary and Jace have been to Pandemonium together. Honestly, it’s probably a little of both. Afterwards, Simon fucks Clary in the back alley because it seems like the kind of thing Jace would do.

Simon wonders what his rabbi would say if he told him he was planning to make WWJD his new guiding principle when it comes to sex.

Friday night date night at Pandemonium becomes a thing.

 

***

 

Simon is having such a good time with Clary that he decides not to worry about his thing anymore. They’re in love. The sex is great. So what if he sometimes thinks about Clary and Jace together? It isn’t hurting anyone. Judging by the way Jace is still moping around like a kicked puppy, making eyes at Clary when she isn’t looking, he isn’t even the only one thinking about it. As long as it stays private, stays secret, he figures it’s pretty harmless.

But as they say, secrets will out.

Clary figures out Simon’s secret one day while they’re having sex in her room at the Institute. As luck would have it, Jace comes knocking when Simon is already balls deep inside Clary’s hot, wet, clenching pussy. Even without his kinky little secret, he can hardly be expected to stop when they’re both so close to coming. At least they remembered to lock the door this time, he thinks absently.

“This isn’t a good time,” Clary calls out to her brother, putting her finger to Simon’s lips to shush him. That’s fine, Simon can do quiet. He fucks Clary slow and deep, brushing against her G spot and sucking on her neck until her toes curl and her eyes roll back in her head a little. If Jace would either shut up or go away, Simon’s certain he could make Clary forget all about her big brother.

But unfortunately for Simon, Clary’s brother does not shut up and does not go away. The stupid fucker keeps banging on the door and hollering about some kind of urgent Shadowhunter briefing. That’s okay — Clary hasn’t exactly told Simon to stop yet — although the situation is clearly starting to make his girlfriend a bit nervous.

“Go away, Jace!” she hollers, her voice high and quick and pressured. And oh yeah, that works for Simon. He literally feels his dick jerk inside her when she says her brother’s name. He tells himself that it’s entirely possible Clary either didn’t notice or didn’t make the connection. Either way, Simon isn’t exactly thinking with his upstairs brain anymore, so he keeps on fucking her slowly, deeply.

Simon has imagined Clary with Jace a million different times in a million different ways. This isn’t the first time for that. Simon and Clary have also done all kinds of covert sexy things in front of and around other people since they started going to Pandemonium. This isn’t the first time for that either. On one memorable occasion, he even went down on his girlfriend while she talked to Izzy about an upcoming mission on her cellphone. This isn’t even the first time for that. But Simon has never dared to imagine how dizzyingly hot it would be to fuck Clary while she talks to her brother through the door.

He can’t help but egg her on a little.

“I’m so close, Clary. Make him go away,” Simon murmurs in his girlfriend’s ear. Clary swallows and nods rapidly, but it takes her a moment to find her voice.

“Not now, Jace!” she calls out eventually, but it doesn’t deter her brother’s annoying habit of banging on her bedroom door one bit. It also does nothing to deter Simon.

“Come on, Clary, make him go away, so I can make you come,” he whispers, breathing hotly against her ear and pinching her nipple. Clary’s eyes fall shut, and she clenches around Simon’s dick like there’s nothing she wants more than an orgasm.

“G-go away, Jace,” she says shakily. “I c-can’t talk right now.”

“Yes, right now, Clary—” Jace is arguing, and Simon’s insides go hot and liquid.

“Yeah, right now, Clary,” Simon purrs, tracing the shell of her ear with his tongue and grinding his pelvis against her clit. “Come for Jace.”

“Oh fuck, Simon,” she breathes, eyes wide with astonishment, and then, she’s tensing and moaning and coming on his dick. Simon starts coming before she even finishes.

They gasp and moan and shake in each other’s arms, sharing a moment of blind ecstasy as they orgasm together and then hold each other through the aftershocks. When they come back to themselves, they can’t hear Jace at the door anymore. Either he gave up or heard them moaning. Logically, Simon should hope for the former, but his dick is kind of hoping for the latter, because apparently, there’s no end to his depravity.

“So that’s your thing,” Clary says softly. “You like it when Jace interrupts us. When he catches us together.” Simon can’t quite bring himself to meet Clary’s eyes, but there’s not much point in denying it after what just happened. Reluctantly, he nods. “And you like thinking about me and him. Together.” Simon nods again. “It doesn’t bother you that he’s my brother?” she asks, sounding more than a little bit lost and confused. Simon hesitates and takes a deep breath.

“That’s part of why I like it so much,” he admits, flushing red with embarrassment. So much for his waning hope that his ability to blush would be diminished by his lack of a heartbeat.

“That’s… That’s really kinky, Simon,” Clary says wonderingly, her expression fitting somewhere between shock and awe. Simon laughs sharply, feeling more and more hysterical as the afterglow fades away.

“I know that, Clary. Why do think I didn’t tell you?”

“Oh,” she says, chewing on her bottom lip for a moment. “Can we keep going to Pandemonium anyway? I’ve really been enjoying that…” Simon blinks at her.

“Aren’t-aren’t you going to break up with me?” he asks haltingly. Clary frowns.

“Why would I break up with you for something that literally gave me an orgasm?” she asks, flushing red but raising her chin to meet Simon’s gaze with determination. The corner of Simon’s mouth draws up in a sheepish, lopsided grin.

“Well, when you put it like that, it does sound kind of dumb,” he admits. “And for the record, I like doing things with you at the club. Privacy is overrated.”

“I knew it!” Clary exclaims with a smug smile.

“I didn’t,” Simon admits, and Clary giggles. “Do you miss being with Jace?” he asks tentatively.

“Sometimes,” she admits, her eyes going serious.

“Does it bother you that you’re brother and sister?” Simon asks gently. Clary hesitates and then nods. “But it doesn’t bother you that I get off on it?”

“No,” she whispers, shaking her head. “Strangely enough, that’s a relief. I tried so hard to stop thinking about him that way once I knew. I thought you’d be disgusted with me if you found out that I still have feelings for Jace, that I’m attracted to him anyway…”

“Oh, Clary,” Simon says softly, reaching out to tuck a stray curl behind her ear. “Even if I wasn’t a kinky fucker, I wouldn’t hold that against you. You can’t help who you’re attracted to, and you didn’t know he was your brother when you fell for him.” At this, Clary gives Simon a small, tremulous smile. “Besides,” he admits with a wicked grin, “I am a kinky fucker, and I think it’s stupidly hot.”

Clary giggles and pulls Simon in for a kiss. Screw the briefing, they decide to go for round two.

**Author's Note:**

> A/N: If you enjoyed the story so far and want to read more, please consider signing the following petition to save Shadowhunters:
> 
> https://www.change.org/p/anyone-who-this-show-has-saved-save-shadowhunters
> 
> #SaveShadowhunters


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